// Copyright 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
//
// This is the main interface for the cast sender.
//
// The AudioFrameInput, VideoFrameInput and PacketReciever interfaces should
// be accessed from the main thread.

#ifndef MEDIA_CAST_CAST_SENDER_H_
#define MEDIA_CAST_CAST_SENDER_H_

#include <memory>

#include "base/callback.h"
#include "base/memory/ref_counted.h"
#include "base/time/tick_clock.h"
#include "base/time/time.h"
#include "media/base/audio_bus.h"
#include "media/cast/cast_config.h"
#include "media/cast/cast_environment.h"
#include "media/cast/constants.h"
#include "media/cast/net/cast_transport.h"

namespace gfx {
class Size;
}

namespace media {
class VideoFrame;

namespace cast {

    class VideoFrameInput : public base::RefCountedThreadSafe<VideoFrameInput> {
    public:
        // Insert video frames into Cast sender. Frames will be encoded, packetized
        // and sent to the network.
        virtual void InsertRawVideoFrame(
            const scoped_refptr<media::VideoFrame>& video_frame,
            const base::TimeTicks& capture_time)
            = 0;

        // Creates a |VideoFrame| optimized for the encoder. When available, these
        // frames offer performance benefits, such as memory copy elimination. The
        // format is guaranteed to be I420 or NV12.
        //
        // Not every encoder supports this method. Use |CanCreateOptimizedFrames| to
        // determine if you can and should use this method.
        //
        // Even if |CanCreateOptimizedFrames| indicates support, there are transient
        // conditions during a session where optimized frames cannot be provided.  In
        // this case, the caller must be able to account for a nullptr return value
        // and instantiate its own media::VideoFrames.
        virtual scoped_refptr<VideoFrame> MaybeCreateOptimizedFrame(
            const gfx::Size& frame_size, base::TimeDelta timestamp)
            = 0;

        // Returns true if the encoder supports creating optimized frames.
        virtual bool CanCreateOptimizedFrames() const = 0;

    protected:
        virtual ~VideoFrameInput() { }

    private:
        friend class base::RefCountedThreadSafe<VideoFrameInput>;
    };

    class AudioFrameInput : public base::RefCountedThreadSafe<AudioFrameInput> {
    public:
        // Insert audio frames into Cast sender. Frames will be encoded, packetized
        // and sent to the network.
        virtual void InsertAudio(std::unique_ptr<AudioBus> audio_bus,
            const base::TimeTicks& recorded_time)
            = 0;

    protected:
        virtual ~AudioFrameInput() { }

    private:
        friend class base::RefCountedThreadSafe<AudioFrameInput>;
    };

    // Callback that is run to update the client with current status.  This is used
    // to allow the client to wait for asynchronous initialization to complete
    // before sending frames, and also to be notified of any runtime errors that
    // have halted the session.
    using StatusChangeCallback = base::Callback<void(OperationalStatus)>;

    // All methods of CastSender must be called on the main thread.
    // Provided CastTransport will also be called on the main thread.
    class CastSender {
    public:
        static std::unique_ptr<CastSender> Create(
            scoped_refptr<CastEnvironment> cast_environment,
            CastTransport* const transport_sender);

        virtual ~CastSender() { }

        // All video frames for the session should be inserted to this object.
        virtual scoped_refptr<VideoFrameInput> video_frame_input() = 0;

        // All audio frames for the session should be inserted to this object.
        virtual scoped_refptr<AudioFrameInput> audio_frame_input() = 0;

        // Initialize the audio stack. Must be called in order to send audio frames.
        // |status_change_cb| will be run as operational status changes.
        virtual void InitializeAudio(
            const FrameSenderConfig& audio_config,
            const StatusChangeCallback& status_change_cb)
            = 0;

        // Initialize the video stack. Must be called in order to send video frames.
        // |status_change_cb| will be run as operational status changes.
        //
        // TODO(miu): Remove the VEA-specific callbacks.  http://crbug.com/454029
        virtual void InitializeVideo(
            const FrameSenderConfig& video_config,
            const StatusChangeCallback& status_change_cb,
            const CreateVideoEncodeAcceleratorCallback& create_vea_cb,
            const CreateVideoEncodeMemoryCallback& create_video_encode_mem_cb)
            = 0;

        // Change the target delay. This is only valid if the receiver
        // supports the "adaptive_target_delay" rtp extension.
        virtual void SetTargetPlayoutDelay(
            base::TimeDelta new_target_playout_delay)
            = 0;
    };

} // namespace cast
} // namespace media

#endif // MEDIA_CAST_CAST_SENDER_H_
